1. Field of the Invention
The invention relates to a gas tube with a heating apparatus, and more particularly, to a gas tube with heating apparatus applied in a chemical vapor deposition (CVD) machine.
2. Description of the Related Art
Chemical vapor deposition is one of the most popular methods for fabricating a thin film. By a chemical reaction, a gas reactant is reacted into a solid product in a reactor, and thus, a thin film of the solid product is formed. The reaction is typically reacted in a substantially high temperature, so that the thermal effect affects the reaction greatly.
During the chemical vapor deposition process, the temperature has a great effect towards the deposition rate and uniformity of the thin film. Thus, to improve the deposition and the uniformity of the thin film, it is important for heating the gas reactant in the transporting tube. In the conventional method, the gas transporting tube is wrapped by a heat tape to raise and keep the temperature of the gas. However, since the heat tape cannot cover the gas tube evenly, moreover, a heat exchange between the heat tape and the external ambient is easily caused, therefore, the heating effect and uniformity of the gas is poor. In addition, after the maintenance of the machine, a longer time is consumed to heat the gas transporting tube up to an operation temperature. Thus, the efficiency of the machine is degraded.